The present invention relates to a manual cleaner in which a roller brush is rotated by the rotation of wheels to pick up dust on the floor and collect it in dust boxes in the cleaner case.
FIGS. 7 and 8 show a prior art cleaner of this type which comprises a case 41 having its bottom open, wheels 43 mounted outside of side plates 42, a roller brush 45 supported so as to extend between the side plates 42 and having driven rollers 44 mounted at both ends thereof, and dust pans 46 provided at both sides of the roller brush 45 to cover the bottom of the case. The rotation of the wheels 43 is transmitted to the roller brush 45 through the driven wheels 44 kept in contact with the wheels 43. Dust on the floor is picked up by the rotating roller brush 45 and collected in dust boxes defined by the dust pans 46 and the case 41.
Each dust pan 46 is pivotally mounted on an axle 47 for a respective pair of wheels 43. The dust pans 46 can be pivoted open downwardly to discharge the dust therein. The dust pans 46 are normally biased by metal springs 48 to such a position as to close the bottom of the case 41.
The wheels 43 are rotated by moving the cleaner back and forth on the floor. The rotation of the wheels 43 is transmitted to the roller brush 45 through the driven rollers 44. The wheels 43 and the driven rollers 44 have to be in close contact with each other while rotating to prevent them from slipping. In order to assure this, the side plates 42 are formed with horizontally elongated axle supporting cutouts 49. The wheels 43 will shift toward the driven rollers 44 so as to be pressed hard against the driven rollers when the cleaner is pushed back and forth. This will allow the torque of the wheels 43 to be transmitted to the driven rollers because the wheels 43 and the driven rollers 44 are free from slipping.
As mentioned above, the dust pans 46 are mounted on the axles 47 for the wheels 43 and the axles 47 are moved back and forth. This means that the dust pans 46 are also moved back and forth with the back-and-forth movement of the wheels 43. Thus clearances are inevitably created between the dust pans 46 and the case 41, through which the dust collected might drop out of the dust boxes.
Another problem resides in the fact that means for biasing the dust pans 46 are in the form of the springs 48 made of a metal. Mounting the metal springs 48 into the case 41 made of synthetic resin is a rather difficult and time-consuming job.
Further, the roller brush 45 has its lower part protruding from the bottom of the case 41. It requires a delicate adjustment to set the roller brush 45 at such a position that it will not press too hard against the floor surface nor too light to pick up dust on the floor.